CDC Guidelines

This page provides a brief overview of the CDC Guidelines for Environmental Infection Control in Health-Care Facilities.

While surfaces can serve as a reservoir of potential pathogens, surfaces are generally not directly associated with transmission of infections to either staff or patients. The transfer of microorganisms from environmental surfaces to patients is via hand contact with the surface. Hand hygiene is important to minimize the impact of this transfer. Cleaning and disinfecting environmental surfaces is fundamental in reducing the potential of cross contamination and contribution to the incidence of healthcare associated infections.

The principles of cleaning and disinfecting environmental surfaces take into account the intended use of the surface or item in patient care. The CDC uses the Spaulding classification for medical and surgical instruments, which outlines three categories based on the potential for the instrument to transmit infection if the instrument is contaminated before use.

Critical – Critical items confer a high risk for infection if they are contaminated with any microorganism. Objects that enter sterile tissue or the vascular system must be sterile because any microbial contamination could transmit disease. This category includes surgical instruments, cardiac and urinary catheters, implants, and ultrasound probes used in sterile body cavities. Most of the items in this category should be purchased as sterile or be sterilized with steam if possible

Semi critical – Semi critical items contact mucous membranes or nonintact skin. This category includes respiratory therapy and anesthesia equipment, some endoscopes, laryngoscope blades, esophageal manometry probes, cystoscopies, anorectal manometry catheters, and diaphragm fitting rings. These medical devices should be free from all microorganisms; however, small numbers of bacterial spores are permissible. Intact mucous membranes, such as those of the lungs and the gastrointestinal tract, generally are resistant to infection by common bacterial spores but susceptible to other organisms, such as bacteria, mycobacteria, and viruses. Semicritical items minimally require high-level disinfection using chemical disinfectants.

Non-critical – Noncritical items are those that come in contact with intact skin but not mucous membranes. Intact skin acts as an effective barrier to most microorganisms; therefore, the sterility of items coming in contact with intact skin is “not critical.” In this guideline, noncritical items are divided into noncritical patient care items and noncritical environmental surfaces.

In 1991 the CDC proposed an additional category for designate environmental surfaces to Spaulding’s original classification to represent surfaces that generally do not come in direct contact with patients during care. Environmental surfaces are further divided into medical equipment such as, x-ray machines, instrument carts and dental units, and housekeeping surfaces such as tabletops, walls, floors etc.